Polymers of the type mentioned in the opening paragraph are known per se. For example, in a publication by Cao et. al. in Synth. Met., 48 (1992), page 91, a description is given of the semiconducting polymer called polyaniline (PANI). Layers formed from the emeraldine salt-form of said polymer exhibit an electric conduction of up to approximately 100 S/cm when use is made of camphorsulphonic acid or dodecylbenzenesulphonic acid as the dopant. In general, the processability of the polymer is adversely affected by the presence of large conjugated chains. For example, processing, from solution, of the undoped electrically insulating form of polyaniline, i.e. the emeraldine base-form, requires the use of N-methylpyrrolidone, an amine or a strong acid, such as concentrated sulfuric acid, as the solvent. These solvents are unattractive for use on an industrial scale. Also the limited choice of solvents forms an impediment to an extensive application of these polymers. Within the art there is a need for semiconducting polymers which, despite the presence of a large conjugated system, exhibit a satisfactory solubility in customary organic solvents and, after doping, a satisfactory conductivity.